Explain the different types of aquatic ecosystems ?

Explanation

Based on the salinity of water, three types of aquatic ecosystems are identified marine, fresh water and estuarine.
i) The marine ecosystem : It is the largest of all the aquatic ecosystems. It is the most stable ecosystem.
ii) Estuarine ecosystem : Estuary, is the zone where river joins the sea, sea water ascends up into the river twice a day (effect of high tides and low tides). The salinity of water in an estuary also depends on the seasons. During the rainy season out flow of river water makes the estuary saline and the opposite occurs during the summer. Estuarine organisms are capable of with standing the fluctuations in salinity.
iii) The freshwater ecosystem : The freshwater ecosystem is the smallest aquatic ecosystem. It includes rivers, lakes, ponds etc., It is divided into two groups the lentic and lotic. The still water bodies like ponds, lakes reservoirs etc., fall under the category of lentic ecosystems wheras, streams, rivers and flowing water bodies are called lotic ecosystems. The communities of the above two types are called lentic and lotic communities respectively. The study of fresh water ecosystem is called as limnology.